Pump.



P. S. CARVER.

PUMP.

APPLICATION FILED APB.. 29, 1909.

Patented July 12, 1910.

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UNITED STATES. PATENT FFICE.

FRED S. CARVER, OF NEW YORK, N. Y.

PUMP.

To all whom t may concern:

Be it known that I, FRED S. CARVER, a citizen of the United States, residing in the borough of Manhattan, city and county of New York and State of New York, have invented certain new and useful Improvements in Pumps, of which the -following is a specification.

This invention relates to compound dou ble acting air pumps and has for its object to provide an improved pump, particularly adapted for use in connection with the inflation of vehicle tires.

yIn this present structure there will be provided a high pressure and a low pressure cylinder arranged side by side in parallel relation, a pair of pistons with their piston rods will be provided and the piston rods will be connected together in some suitable manner, as for instance by means of a handle. The object of this being to move'the pistons together. The low pressure piston, while moving in each direction, will force the air into the high pressure cylinder behind the piston in such cylinder, so that after the high pressure piston has completed its stroke in either direction a charge of air compressed from the first stage will be ready in such cylinder to be compressed out upon the opposite stroke of the piston in such high pressure cylinder.

In the drawings accompanying and forming part of this specification Figure l is a longitudinal section of a form of my improved pump. Fig. 2 is a section taken at about right angles to Fig. 1 on a somewhat enlarged scale, the parts being broken away in a middle zone. Fig. 3 is a cross section taken at about the plane of line 343 of Fig. 1. Fig. 4 is a detail showing one of the inlet valves to the low pressure cylinder; and Fig. 5 is a section on the line 5-5 of Fig. 1.

'In the present illustration there is shown a low pressure cylinder 1 and a high pressure cylinder 2 of smaller diameter than the low pressure cylinder. These cylinders are arranged side by side and are disposed in parallelism, being held in such position by means of a base plate 3 and a top plate 4. The base plate in the present instance will alford the foot piece for the use of the operator, and the top plate will carry suitable stuffing boxes for the piston rods. There is shown a double acting piston 5 in the low pressure cylinder and a double acting piston Specification of Letters Patent.

Application filed April 29, 1909.

`Patented July 12, 1910.

Serial No. 492,844.

6 in the high pressure cylinder. rIhe pistons will each be constructed for double action, that is for having an effective or compressing stroke in each direction. One practicable form of construction of double acting pistons is illustrated herein and will be described later. The pistons are provided respectively with piston rods 7 and 8 which are connected together by being connected to a handle 9.

Assuming the pistons to be in the position illustrated in Fig. 1, the handle upon being raised will raise both of the pistons 5 and (3. The piston 5 will draw air into the cylinder 1 through the inlet port 1() and past the valve l1 which it will unseat for this purpose. As the piston 5 rises it will compress the air in front of it in the low pressure cylinder l and force this out of the port 12 at the top of such cylinder. The valve 13 will be closed and the air will pass down the tube 14 unseating the valve 15, and passing by means of the port 16 into the lower end of the high pressure cylinder and behind the piston 6 as this is rising. During the rise of the high pressure piston 6 the air which is above it in the cylinder 2 will be forced dout of the port 17 down the tube 18, unseating the valve 19, and passing out through the passage 20, past the valve 200, to the discharge 21. After the pistons have reached the top of the cylinder a charge of air at atmospheric pressure will be in the low pressure cylinder 1 below the piston 5, and a charge of compressed air will be in the high pres sure cylinder 2 below the piston 6 therein. Upon the down stroke of both pistons, the low pressure piston 5 will draw in a charge of air through the inlet 22, unseating the valve 13 and passing into the cylinder l through the port 12. The air below the piston 5 will be compressed and forced through the port 10 when it will seat the valve 11 and pass up the tube 2G, unseating the valve 23 and passing into the high pressure cylinder' 2 at the port 24 at the rear of the piston 6 as this is descending. In its descent the piston 6 will force the air below it past the valve 25 and into `the channel 20.

From the foregoing it will be seen that each movement of the handle moves both pistons inthe same direction, and that each will act in both movements of reciprocation, thus we find that the pump is twin cylinder, compound, double acting. It will also be seen that a strong and eticient structure is provided in which the parts are compactly arranged.

Mention is above made to the fact that the pistons are double acting. The piston 5 is in the present illustration provided With cup leathers 27-28 projecting in opposite directions so as to make this piston double acting. The rod for this piston is packed with oppositely directed packings 29 and The piston 6 is also provided With oppositely directed cup leathers {3l- 32, and the rod for this piston is packed with a packing 33. The packing of the pistons enables each to compress the air at that side toward Which the piston is moving. In the present illustration the cup leather at each side will be effective upon piston movement toward such side.

Having described my invention I claim:

l. In an air pump, the combination With a low pressure cylinder and a high pressure cylinder disposed side by side, of a double acting piston in each cylinder, means for carrying the cylinders, means for carrying the pistons, one of said carrying means embodying a handle and the other of said carrying means embodying a foot piece, each of said cylinders being provided at each end With a port, and tubes connecting the ports at the respective ends of the low pressure cylinder with the ports at the opposite ends of the high pressure cylinder, said tubes being disposed between the cylinders.

2. In an air pump, the combination with a high pressureV cylinder and a 'low pressure cylinder, these being disposed side by side, a double acting piston in each cylinder, each of said pistons embodying a pair of cup leathers projecting in directions opposite one to the other, a piston rod connected to each piston, a handle fast With both of the piston rods, a foot piece fast With the lower end of each ofv the cylinders, a single port at each end of the low pressure cylinder having an opening to the atmosphere, a back pressure valve at such opening, a port at each end of the high pressure cylinder, a

tube extending from the port at the lower end of the low pressure cylinder to the port at the upper end ot' the high pressure cylinder and a tube extending from the port at- Athe upper end of the loW pressure cylinder to the port at the lower end of the high pressure cylinder, a discharge, and means of communication between the respective ends of the high pressure cylinder and the discharge.

FRED S. CARVER. IVitnesses:

CHAS. LYON RUSSELL, FRED. J. DOLE. 

